CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowances aggregating	$ 15,729	$ 23,704
Permits and other intangibles, accumulated amortization	67,035	60,633
Closure and post-closure liabilities, current portion	6,313	5,849
Remedial liabilities, current portion	$ 9,313	$ 8,669
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Authorized shares (in shares)	80,000,000	80,000,000
Common stock, issued shares (in shares)	52,986,122	52,772,392
Common stock, outstanding shares (in shares)	52,986,122	52,772,392